LF: Re: adding a L into a 300m LF vertical?

["James Moritz" <james.moritz@btopenworld.com>]

Dear Stefan, LF Group,

> _Questions:_ Is my calculation reasonably useful? Would YOU add that
> coil in a height of 100m above GND?
I have found with NEC simulations that they give you a reasonable idea of 
the impedance, but not a precise value. Especially for the resistance, where 
there are many unknowns - NEC really only sets a lower limit.
On the basis of the calculations, I would first try without the coil, then 
if results are as expected, I would try it with the coil. Otherwise there 
are too many variables to make sense of the experiment - if the coil goes up 
and the impedance is totally different from the calculation, is it because 
of the coil, the antenna, or the calculation?
> I tend to let it be since the improvement isn't that much and the effort
> is high. Furthermore the coil losses could be higher since i have to use
> a thin wire to keep the weight small...
Yes - the 136k coils I have made with Q > 300 have been rather big, either 
with RF Litz wire or thick solid wire.
Hope to see some signals at the weekend,

Cheers, Jim Moritz
73 de M0BMU